Liquid-feed system



March 24, 1931.

c, STOKES LIQUID FEED SYSTEM Filed March 8, 1923 INVENTOR. 54444.72,

Patented Mar. 24, 1931 UNITED STATES CHARLES LAWRENCE STOKES, OF LOSANGELES, CALIFORNIA LIQUID-FEED SYSTEM Application filed March 8,

My invention relates to improvements in vacuum tanks, used for supplyingliquid fuel to the carburetor of an internal combustion engine from alow level.

The principal object of my invention is to provide apparatus forincreasing the pumping efficiency of the vacuum tank and at the sametime continuously withdrawing normally waste vapors therefrom.

A further object of my invention is to provide a priming, or starting,apparatus in conjunction with the vacuum tank and the vapor withdrawingapparatus.

Another object of my invention is to provide improved evaporatingapparatus in conjunction with the vacuum tank.

In the accompanying drawings which illustrate the invention,

Fig. 1 is a vertical section through a vacuum tank equipped with thepresent improvement.

F ig. 2 is an elevation showing the tank in operative relation with anengine and its carburetor.

With reference to the'drawing of Fig. 1,

1 indicates the outer shell, or reservoir, of a well-known type ofvacuum tank, known as the Stewart Warner vacuum tank, which is selectedto illustrate my invention, although it is to be understood that theinvention is not limited to the specific structure shown, but may beused in connection with many similar types of vacuum tanks. -2 is theinner chamber, or suction chamber, for the reception of fuel from a lowlevel tank (not shown) through a passageway 20. 3 is a cap, circular inform, which is held together with 2 and 1 by a number of screws aroundthe periphery thereof. I

In place of one of the screws, I insert a fitting 6, in which is placeda floating valve comprising ahollow stem 7 to which is attached a disc8, which has on its upper part a cushion of cork 9.

Inside of 2 is the usual float 4 which serves to operate suction valve18 and air valve 19 depending on the liquid level in 2. The float operats the valves through the medium of levers and springs (not shown), butinasmuch as the general construction of the tank is well 1923. SerialNo. 623,687.

known 'in the art and is not herein claimed, it is not considerednecessary to be enlarged upon. In Fig. 1, suction chamber 2 has justdischarged its contents into 1 and air valve 19 is closed and suctionvalve 18 has just opened and the liquid fuel level is now shown as X-X.

As illustrated in Fig.2, suction is applied to 2 from the inlet manifold14 of an internal combustion engine 21 through a pipe 12, which isconnected through 13 to the interior of 2 and through a fitting 11 it isconnected through 6 into the interior of 1.

A passage 15 is generally cored out in 3 to suppl air to 1 and I nowextend 15 by a pipe 1 which pipe is so arranged that its lower extremityis just above the normal liquid level in 1.

Valve stem 7 is made of very thin and light tubing and has its lower end(when there is no suction applied through 12) about onehalf inch belowthe normal liquid level in 1. The upper end of 7 is restricted by asmall orifice 10, which governs the amount of liquid passing through 7and thereafter the amount of air and vapors passing therethrough.

Two small holes 17 are placed in the wall of a, i'lhich holes are aboutthe size of a No.

In my reissue Patent No. 14,701 dated July 29, 1919, and others, I havedescribed a pioneer method of continuously withdrawing carburetted airfrom a vacuum tank, and in my co-pending application S. N. 512,187,filed November 2, 1921, and Patents Numbers 1,525,698 dated February 10,1925, and

1,488,566, dated April 1, 1924, I have de- I scribed diflerent methodsof continuously withdrawing air from the inner and outer chambers of avacuum tank of a different type. My present invention shows an improvedmethod of pumping fuel over said copending applications, inasmuch as Inow considerably increase the pumping efliciency of the vacuum tank bymaintaining a slightly greater vacuum in reservoir 1 over that contained in suction chamber 2 when the latter is not drawing liquid fuelthereto from a lower level. At the same time I increase materially thevaporization of light fractions from the liquid fuel contained in 1 bypass- .ing thereover a constant stream of air (which may be heated air)and feed the same continuously to the engine, the air being used at thesame time to vent the reservoir 1 and thereby permit liquid fuel to runby gravity through a discharge connection 5 to a carburetor 22 connectedto manifold 14.

The operation is as follows 2-- If it is assumed that the engine 21 isabout to be started, upon cranking the engine vacuum applied through 12to 2, is applied in the same degree to chamber 6, whereupon 7 is rapidlyelevated, due to atmospheric pressure through 16 applied to the lowerside of disc 8, and is seated in the lower part of 11. Liquid fuel isalso elevated with 7, and the amount thereof is gaged by the size of theinterior of 7 and the depth to which the lower part of 7 is immersedbelow the liquid level XX.

The liquid fuel is then withdrawn rapidly through IO'and 12 to theengine, thereby furnishing a priming charge for starting it and, as soonas the liquid fuel in 7 is withdrawn, air is continuously withdrawn tothe engine by its suction together with the normally waste vapors givenoff by the liquid fuel contained in 1.

As long as the engine operates, its suction holds 8 securely to its seatin the bottom of 11, and this seat is made substantially air tightby'the addition of the cork gasket 9. It will be seen that the passageof air and vapors through 7 will be unrestricted except by orifice 10,because the lower end of 7 will be elevated above the liquid level XX bythe engine suction.

As soon as the application of suction is discontinued through 12, aswhen the engine is stopped, 8 and '7 fall to their seat in the lowerpart of 6, as shown in the drawing, by gravity.

The application of a draft of air across the surface of a body ofgasoline materially increases the rate of vaporization, and I find bywithdrawing the -light fractions from gasoline, and mixing them againwith heavy atomized fractions in an engine manifold, I am enabled to getgreat economy, as well as increased efficiency in the actions of anengine. Therefore pipe 16 is placed so as to be normally above theliquid level X--X.

With the intermittent type of vacuum tank as illustrated, during thegreater time of engine operation, the discharging periods of 2 and 1,are much greater than the pumping period of 2, therefore, during suchdischarging periods, the application of engine suction through 7 to 1 issuch that there is a slight degree of vacuum maintained in 1, over thatmaintained in 2 when 2 is open to atmosphere through 19. In this manner,after a quantity of gasoline has been drawn into 2 and when 18 is thenclosed and 19 opened, this slight degree of vacuum in 1 will hasten thedischarge of liquid from 2 into 1 very materially and thus, in a giventime, I am enabled to passa greater quantity of liquid fuel through 2than under normal con ditions witho at my improvements.

At the same time, I continuously withdraw vapors from gasoline throughholes 17, which are of such a size as to maintain the difi'erentialvacuum 1 and 2 alreadyidescribed. I find the amount of vacuum to bemaintained in 1 is about one inch of gasoline vacuum.

It is obvious that fitting 6 and valve 7 may be placed in otherpositions in a liquid feed system, such as the float chamber of acarburetor, or in any position where theliquid to be fed to 7 is undersubstantially-atmospheric pressure, but in the present instance 7performs a double function of passing liquid fuel first and secondlycarburetted air to the engine.

I claim 1. A vacuum tank having a suction chamber and a reservoir incombination with means to apply suction to the suction chamber andreservoir, means to continuously supply air to the reservoir, means tocontinuously withdraw air from the reservoir and means to intermittentlywithdraw air from the suction chamber through the reservoir.

2. A vacuum tank having a suction chamher and a reservoir in combinationwith means to apply suction to the suction chamber for drawing liquidfuelthereto, means to discharge liquid fuel from the suction chamber tothe reservoir, means to discharge liquid fuel from the reservoir, meansto supply air to the reservoir, means to apply suction to the reservoir,and means under influence of the same suction as applied to the suctionchamber for withdrawing liquid fuel initially and air thereafter fromsaid reservoir.

3. A vacuum tank having a suction chamber and a reservoir in combinationwith means to apply suction to the suction chamber for drawing liquidfuel thereto, means to discharge liquid fuel from the suction chamber tothe reservoir, means to discharge liquid fuel from the reservoir, meansto pass air close over the. surface of the liquid fuel in the reservoir,means to apply suction, and means under influence of the same suction asapplied to the suction chamber for withdrawing liquid fuel initially andair thereafter from said reservoir.

4. In a liquid feed system for internal combustion engines thecombination with a reservoir for supplying liquid fuel to the engine ofa conduit for applyin the engine suction to the reservoir, an ori ce forsupplying air to the reservoir and a valve in the conduit actuated bythe engine suction, said valve having communication with the reservoirand initially being in communication with the liquid therein, whereby aprede- -fuel thereto, a. valve for discharging liquid termined amount ofthe liquid fuel is initially fed to the engine and thereafter said airis continuously passed through said valve to the engine. w

5. In a liquid feed system for internal combustion engines, thecombination with a reservoir for sup -qiving liquid fuel in the engineof a conduit for applying the engine suction to the reservoir, a passa eadapted to supply air close over the sur' ace of the liquid fuel in thereservoir an: val e conduit actuated by the engine iction. valve havingcommunication with the i voir and initially being in communication withthe liquid therein, whereby a predetermined amount of the liquid fuel isinitially fed to the engine and thereafter said air is continuouslypassed through said valve to the engine.

6. A vacuumtank embodying a suction chamber and a reservoir, incombination with a conduit for applying suction to the suction chamberand reservoir to draw liquid starting an internal combustion engine,comprising a liquid fuel reservoir, a suction pipe, a conduit leadingfrom the reservoir to said suction pipe, said reservoir having an airinlet, and movable means for initially supplying any excess of liquidfuel from the reserto said suction pipe upon starting the engine, saidmeans being adapted to be disconnected from the liquid fuel by saidsuction for thereafter supplying air 10 the enll. Means for providingexcess fuel for starting an internal combustion engine, comprising aliquid fuel reservoir, a conduit leading from the reservoir to a suctionpipe of the engine, said reservoir having an air inlet, and an automaticvalve having a hollow stem adapted to pass excess liquid fuel and air tothe engine responsive to its suction upon starting the same.

12. Means for providing excess fuel for starting an internal combustionengine, comprising a liquid fuel reservoir, a conduit leading from thereservoir to a suction pipe of the engine, said reservoir having an airinlet and a valve having a hollow stem adapted to pass excess liquidfuel and air to the engine responsive to its suction upon starting thesame and adapted to be cut off from the liquid fuel by said suction forthereafter supplying air to the engine.

1.3. Means for priming an internal combustion engine comprising a liquidfuel reservoir, conduit leading from the reservoir to a suction .pipe ofthe engine, said cond t having a valve seat, and an automatic valvenaving a hollow stem adapted initially to pass liquid fuel from thereservoir to the engine and operable by the suction of the engine toengage said seat after a predetermined amount of liquid fuel has beenmeasured by said valve upon starting the engine.

14. Means for priming an internal combusfuel from the suction chamber tothe reservoir, a passage for supplying air to the res ervoir and a valvein said conduit comprising a hollow stem having its lowerend extendingbelow the liquid level in the reservoir when atmospheric pressureprevails in said conduit and adapted to have its lower end raised abovethe liquid level when vacuum prevails in said conduit. p

'7. Means for priming an internal combustion engine including a liquidreservoir, an intake passage. a throttle in said pas. e, a suction pipein communication with said intake passage above said throttle, a conduitleading om the reservoir to said suction pipe i sling a suction operatedlZllS1i;i.;f val e the coiu it adapted to supply predeiermined quantityof liquid from tie r 'ervoir upon starting the engine.

8. Me s for priming an internal combustion engine comprisingaliquid fuelreservoir, tion en; including J's iiqr TQSQL voir, an a conduit leadingfrom the reservoir to a sucintaize pa throttle in said passage, 5. tionpipe of the engine, said conduit having a suction p In communicationwith said invalve seat, and an automatic valve having a pass. 1 abovesaid throttle, a conduit hollow stem adapted initially to pass liquid le"11g n the reservoir to said suction fuel from the reservoir to theengine and pipe and means including an automatically operated measarivalve in the condult adapted to supply a predeterminedquantity of liquidfrom the reservoir upon starting the engine.

9. Means for providing excess fuel for starting an internal combustionengine, comprising a liquid fuel reservoir, a conduit lead ing from thereservoir to a suction pipe of the engine, said reservoir having an airinlet. and means including an automatically operated valve in saidconduit adapted to initially supply excess fuel from the reservoir uponstarting the engine and thereafter to suppl air to the enginefrom thereservoir.

10. eans for providing excess fuel for operable by the suction of theengine to engage said seat after a predetermined excess of liquid fuelhas been measured by said valve upon starting the engine said valvebeing engaged with said seat substantially While engine suctioncontinues and supplying air to the engine while in such position.

15. A vacuum tank for an internal combustion engine comprising a suctionchamber and a reservoir, in combination with means to ap ply enginesuction to said chamber to draw liquid fuel thereinto, means todischarge liquid fuel from said chamber to said reservoir, means tosupply air to the reservoir, means to apply suction to the reservoir,and means under influence of the engine suction and initially connectedwith the liquid fuel in the reservoir for passing an excess of fueltemporarily to the engine and movable to cut off communication with saidliquid and for passing air thereafter from the reservoir to the engine.

16. Apparatus for passing an excess of liquid fuel to an internalcombustion engine, including a liquid fuel reservoir and a valve movableby the engine suction; said valve having a portion to be seated, ahollow stem and an orifice at its discharge end for controlling the rateof passage of liquid fuel therethrough.

17. In combination, an internal combustion engine having an intakepassage, a liquid reservoir, a suction pipe between saidreservoir andintake passage, and means for priming said engine, said means comprising.1. a slidable tube having one end below the liquid level in saidreservoir during the nonoperation of the engine and having its oppositeend in communication with said suction pipe, said tube beingautomatically mov- 5 able by the engine suction to a position above saidliquid level during the operation of the engine.

18. Means for introducing a priming charge to an internal combustionengine inac eluding a liquid fuel reservoir having a passage and'a valvein said passage movable by engine suction for controlling the fiow of'priming charge to the intake manifold of the en 'ne, and meansassociated with the valve or metering the quantity of fuel admitteddurin each priming period.

Signed at l%ilmington, in the county of Los Angeles and State ofCalifornia, this 20th day of February A. D. 1923.

40 CHARLES LAwaENcE STOKES.

